Abstract
The main purpose of this report was to know the effects of growth stage in making silage, on pH, organic acids composition, digestibility and nutrients intake by dairy cows. 1) First growth of orchard grass and Ladino clover mixture was harvested four times at two weeks interval on the same field from 4th of June 1966 in 2 tons experimental pilot silo under the same treatments without preservative. Herbage was cropped by mower bar type's forage harvester. 2) Results are summarized in the following Table 1. 3) Dry matter yield of the pasture was reached maximum at heading stage, but crude protein contents in dry matter basis decreased in the order of harvesting date. 4) Earlier harvested silages contained higher dry matter per cubic meter than later harvested ones. 5) Maximum fermentation temperature was closely related to air temperature of ensiled day. Also, even in the small pilot silo, higher fermentation temperature was observed in upper layer. 6) From the point of pH, organic acids and ratio of ammoniacal nitrogen to total one were improved in the order of growth stages until flowering, but very poor at the seed setting stage. 7) DDM content of the silage was indicated higher in earlier stage. Significant negative correlation (r : -0.969) was found between growing days of the pasturage (X) and TDN content in the silage (Y%). The regression equation was Y=101.37-0.66 X. And also, a significant correlation, (r : -0.938) was shown between the growing days (X) and DCP % in dry matter basis (Y%). The regression equation was obtained Y=18.65-0.18X. 8) TDN intake of the silage by cow was rapididly decreased after flowering stage. Significant negative correlation, (r : -0.609) was shown between growing days (X) and TDN intake of the silage (Y kg). The regression equation was Y=10.48-0.086X. 9) Silage evaluation should be decided after general consideration of pH, organic acids, digestibility and nutrients intake by cow. 10) From the view point of general silage evaluation and production of the pasture, heading stage but before flowering may be recommended as favorable growth stage in making high moistore silage.
